The drift of some Tory MPs into a moralising absolutism is as big a threat as Ukip to the party's election chances.

There has been a fair amount of commentary around today about Lord Ashcroft’s latest jumbo opinion poll. The Tory peer's particular area of interest on this occasion is the views of people who vote Ukip or consider doing so. The top line conclusion – literally the headline that Ashcroft puts on his blog – is that hatred of the European Union is not the chief driver of support for Nigel Farage’s party. Crime and immigration are much bigger factors.

That confirms previous findings as does the excavation of data to show that it isn’t just Tory voters defecting to Ukip. The party is peeling away support from Labour and the Lib Dems too, although not at the same rate as it secures Tory defectors. (The Times led this morning with its own poll showing a Ukip surge eating into David Cameron’s base.)

There is a lot to digest in the report but one point leaps out. Ukip supporters know theirs is a protest vote, in the sense that they want to send an explicit signal of anger to Westminster mainstream parties. They believe Farage says things that no-one else has the courage to say about the decline, decay and corruption of British life. Voting Ukip, in other words, is to some extent a qualitatively different kind of electoral participation to voting for Labour, the Lib Dems or Tories. It is an act of ballot box rage, not necessarily a granting of permission to govern. Ashcroft summarises some of his focus group responses as follows:

“They are pessimistic, even fearful, and they want someone and something to blame. They do not think mainstream politicians are willing or able to keep their promises or change things for the better. UKIP, with its single unifying theory of what is wrong and how to put it right, has obvious attractions for them …

[They are] part of a greater dissatisfaction with the way they see things going in Britain: schools, they say, can’t hold nativity plays or harvest festivals any more; you can’t fly a flag of St George any more; you can’t call Christmas Christmas any more; you won’t be promoted in the police force unless you’re from a minority; you can’t wear an England shirt on the bus; you won’t get social housing unless you’re an immigrant; you can’t speak up about these things because you’ll be called a racist; you can’t even smack your children.”

The list of complaints will be familiar to anyone who has ever spoke to BNP voters. It is a mix of misconstrued and exaggerated claims about “political correctness gone mad” with quite paranoid delusions. (Where can you not fly a George Cross, for goodness sake? During a major football tournament is hard to avoid one.) There is also a whiff of hostility to the idea of an arrogant do-gooder government meddling in people’s life, expressed in Ashcroft’s list as a frustrated urge to smack children.

I have come across the same sentiment when speaking to former Labour voters who backed the BNP in 2010 with regard to the smoking ban. It wasn’t a big electoral issue in Westminster but it plainly got right on the nerves of some people who thought depriving them of a fag in the pub was adding insult to the wider injury of opening the floodgates of immigration and handing out council houses to foreigners. Ukip has found a special niche in the British political market place for a far right party that looks respectable.

These anti-politics, anti-government ideas are becoming quite deeply embedded in parts of British society. It is worth pointing out that, while Ukip is clearly causing the most anxiety for the Tories at the moment, a cultural phenomenon that sees government as pernicious and politics as an expression of arrogance and venality is bad news for the left.

Ed Miliband is finding it hard enough persuading people to trust Labour with their money when so many think the party splurged it all the last time they were in power. That task is not going to be made easier when people also think any government by a mainstream party will make self-serving choices and can’t be trusted. Conservatives have at least developed a way of speaking to the public that concedes the basic point that state action is more likely to be pernicious than helpful. Labour has to rehabilitate the whole idea of government intervention before it can sell itself as the most desirable interveners on the shelf.

There is every chance that a lot of those voters currently saying they support Ukip will drift back to a mainstream party for a general election. In that case, it is a reasonable assumption that of those returning to more established political homes, a majority will go to the Tories. Combine that with some trickle back from Labour to the Lib Dems (as is not impossible if the economy picks up a bit and memories of old tuition fee perfidy fade) and Ed Miliband’s lead looks quite vulnerable.

It is also quite possible that there is now a permanent fracture between those who think politics is a creditable pursuit practiced by established professionals and those who think it is all villainy. The emergence of an anti-Westminster cult – a new political hierarchy that puts moral distance from the capital at its apex – is strongly reminiscent of the American Tea Party movement with its histrionic abhorrence of Washington elites (and its tendency to conjure up fictional conspiracy against the mainstream white Christian culture).

The Tories would be well advised to consider the comparison. Lib Dems already like to deride a “Tea Party” element on Cameron’s back benches. It has been out in force in recent weeks during debates over Europe and gay marriage. There lies the greater long-term threat to Conservative election chances. Defection of Conservative supporters to Ukip is plainly a problem for the Prime Minister, although many can be won back once they have given Brussels a kicking in 2014 elections to the European parliament. As big a danger is the drift of some Tory MPs into a moralising absolutism. They brook no compromise and eye with unhidden envy Ukip's basking in anti-politics outrage. It isn’t just the angry voters Cameron needs to worry about, it is the Tea Party tendency that the anger brings out in his own party.